Missing Coin Sum

#include <bits/stdc++.h>

using namespace std;

long long missing_coin_sum(multiset<long long> &m) {
    long long min_sum = 1;

    auto it = m.begin();
    while (it != m.end()) {
        long long coin = *it;
        if (coin > min_sum) {
            return min_sum;
        }
        else {
            min_sum += coin;
        }
        ++it;
    }
    return min_sum;
}

int main()
{
    // ios_base::sync_with_stdio(0);
    // cin.tie(0);

    long long n;
    cin >> n;

    multiset<long long> m;
    for (long long i = 0; i < n; ++i) {
        long long x;
        cin >> x;
        m.insert(x);
    }

    cout << missing_coin_sum(m) << "\n";
}

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED